EP 0389749 A3 19911211 - APPLIANCE FOR MEASURING ELECTRICAL POWER OR ENERGY
Title (en)
APPLIANCE FOR MEASURING ELECTRICAL POWER OR ENERGY
Publication
Application
Priority
CH 118589 A 19890331
Abstract (en)
[origin: EP0389749A2] The arrangement contains in each case one current-fed transformer (10) and one voltage input (18) per phase, both of which are connected to an associated subsequent mark/space pulse amplitude modulator (13;14) existing for each phase, which in each case consists of a mark/space modulator (13) and a pulse amplitude modulator (14). Each transformer (10) is connected via an integrator (11) exhibiting a high-impedance input to the mark/space pulse amplitude modulator (13;14). The pulse amplitude modulator (14) exhibits two push-pull operated outputs which are each connected to an input of an arrangement for integrating the areas of pulses and spaces which exist in operation at the output of the pulse amplitude modulator (14). Furthermore, there is also a phase shifter (12), a resistor (15a), a VDR resistor (15b) and a capacitor (15c). A processing and display device (4;5;6;7;8) consists of a current/frequency converter (4), a frequency divider (5), a matching circuit (6), a display (7) and a light-emitting diode (8). Of the two phase shifters (12) drawn, there is in each case only one in existence. The current/frequency converter (4) contains the arrangement for integrating the areas, constructed by means of an operational amplifier (25), four switches (21, 21a, 22, 22a), two current sources (23, 23a) and a logic circuit (24). The arrangement is efficient and can be built up by using commercially available components and a customised integrated circuit which contains all semiconductor components. <IMAGE>
IPC 1-7
IPC 8 full level
G01R 21/127 (2006.01)
CPC (source: EP US)
G01R 21/127 (2013.01 - EP US)
Citation (search report)
- [X] US 4182983 A 19800108 - HEINRICH THEODORE M [US], et al
- [A] EP 0049520 A1 19820414 - SQUARE D CO [US]
- [A] GB 2094989 A 19820922 - TOKYO SHIBAURA ELECTRIC CO
- [A] IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, Band IM-36, Nr. 1, März 1987, Seiten 54-59; A.C. CORNEY et al.: "Digital sampling laboratory wattmeter"
Designated contracting state (EPC)
CH DE ES FR GB IT LI NL
DOCDB simple family (publication)
EP 0389749 A2 19901003; EP 0389749 A3 19911211; CH 681491 A5 19930331; US 5032785 A 19910716
DOCDB simple family (application)
EP 90101576 A 19900126; CH 118589 A 19890331; US 49834590 A 19900323